Changes in hemostatic parameters in hepatic veno-occlusive disease following bone marrow transplantation

Analysis of laboratory parameters before the occurrence of hepatic sinusoidal obstruction syndrome in children, adolescents, and young adults after hematopoietic stem cell transplantation

PURPOSE

Hepatic sinusoidal obstruction syndrome (SOS) is a serious complication following hematopoietic stem cell transplantation (HSCT) in which early diagnosis improves patient outcome. The aim of our study was to detect laboratory parameters following HSCT that can predict the occurrence of SOS.

METHODS

This retrospective study included 182 children, adolescents, and young adults who underwent allogeneic or autologous HSCT for the first time (median age 7.2 years). The diagnosis of SOS was based on the pediatric criteria of European Society for Blood and Marrow Transplantation (EBMT). We investigated 15 laboratory parameters after HSCT before the onset of SOS.

RESULTS

The overall incidence of SOS was 14.8%. SOS developed in 24 of 126 allogeneic (19.1%) and in 3 of 56 autologous (5.4%) HSCT patients at a median time of 13 days after HSCT. We observed a low SOS mortality rate of 11.1% within 100 days after HSCT. International normalized ratio (INR) ≥ 1.3, activated partial thromboplastin time (aPTT) ≥ 40 s, reptilase time ≥ 18.3 s, factor VIII ≤ 80%, antithrombin III ≤ 75%, protein C ≤ 48%, D-dimer ≥ 315 µg/L, bilirubin ≥ 9 µmol/L, and ferritin ≥ 3100 µg/L showed significant associations with the onset of SOS in the univariate analyses. In the multivariate analysis, INR ≥ 1.3 [odds ratio (OR) = 8.104, p = 0.006], aPTT ≥ 40 s (OR = 10.174, p = 0.001), protein C ≤ 48% (OR = 5.215, p = 0.014), and ferritin ≥ 3100 µg/L (OR = 7.472, p = 0.004) could be confirmed as independent risk factors after HSCT before SOS. If three of the four significant cut-off values were present, the probability of developing SOS was more than 70%. The probability of SOS was 96%, if all four laboratory parameters were changed according to the cut-off values. The values of factor XIII, von Willebrand factor (vWF), von Willebrand factor activity (vWF activity), protein S, fibrinogen, and alanine aminotransferase (ALT) were not relevant for the occurrence of SOS.

CONCLUSION

In summary, the laboratory parameters INR, aPTT, protein C, and ferritin were very useful to predict the occurrence of SOS. In addition, this is the first report on a significant association between SOS and high values of INR and aPTT after HSCT before SOS.

Hypofibrinolysis in pediatric patients with veno-occlusive disease in hematopoietic stem cell transplantation

PURPOSE

Veno-occlusive disease (VOD) is a serious complication of hematopoietic stem cell transplantation (HSCT) with a high incidence in pediatric patients. This study aimed to detect signs of hypofibrinolysis using thrombelastography.

METHODS

In this prospective single-center study, thrombelastographic measurements (EX and TPA tests) were taken during HSCT to detect signs of impaired coagulation, clot formation, or hypofibrinolysis.

RESULTS

Of 51 patients undergoing allogeneic and autologous HSCT, five (9.8%) developed VOD and received defibrotide treatment. Thrombelastography measurements were also obtained from 55 healthy children as a control group. The results show that clot lysis was prolonged in VOD patients compared to other HSCT patients and control group (lysis time, TPA test: day + 14 to + 21: VOD: 330 ± 67 s vs. HSCT: 246 ± 53 s; p = 0.0106; control: 234 ± 50 s; control vs. VOD: p = 0.0299). The maximum lysis was reduced in HSCT patients compared to controls (EX test: control: 8.3 ± 3.2%; HSCT: day 0 to + 6: 5.3 ± 2.6%, p < 0.0001; day + 7 to + 13: 3.9 ± 2.1%, p < 0.0001; day + 14 to d + 21: 4.1 ± 2.3%, p < 0.0001).

CONCLUSION

These results suggest that HSCT patients exhibit reduced fibrinolytic capacities and patients diagnosed with VOD show signs of hypofibrinolysis. This prospective study shows that fibrinolysis can be assessed in a rapid and accessible way via thrombelastography. Thrombelastography might be a parameter to support the diagnosis of a VOD and to serve as a follow-up parameter after the diagnosis of a VOD.

Prognostic Biomarkers for Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome in Myeloablative Allogeneic Hematopoietic Cell Transplantation: Results from the Blood and Marrow Transplant Clinical Trials Network 1202 Study

Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation (HCT). This study aimed to determine a blood biomarker signature early post-HCT that identifies patients at high risk for VOD/SOS. A set of 23 plasma biomarkers, selected from the VOD/SOS literature, was measured on days 0, 7, and 14 after myeloablative HCT using blood samples from patients enrolled in the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Protocol 1202. Eligible cases were diagnosed with VOD/SOS in BMT CTN 1202 using the Baltimore criteria. Controls (without VOD/SOS) were matched to cases for conditioning regimen and age. Significant biomarkers were identified using the Bonferroni-adjusted Wilcoxon rank-sum test (P ≤ .002). Thirty-three patients with mild or severe VOD/SOS were identified (cases) and matched to 107 controls. Two, 8, and 5 biomarkers measured from the plasma of these patients were significantly associated with the development of VOD/SOS at days 0, 7, and 14, respectively, with the strongest associations on days 7 and 14. Biomarker associations were stronger for severe VOD/SOS risk and were stronger prognostic markers for VOD/SOS cases occurring within 28 days of HCT. Hyaluronan was most strongly associated with VOD/SOS risk, with an area under the receiver operating characteristic curve (AUC) of .81 on day 7 and .79 on day 14. Multivariate models of up to 5 biomarkers generated AUCs ranging from .82 to .85. All associations with VOD/SOS risk were independent of clinical risk factors. This study confirms previously identified biomarkers of VOD/SOS risk and identified novel prognostic biomarker signatures that identify patients at risk for VOD/SOS shortly after HCT. Multivariate analysis suggests that a combination of up to 5 of these protein biomarkers may provide a prognostic tool for identifying patients at risk for VOD/SOS.

Efficacy and Safety of Recombinant Thrombomodulin for the Prophylaxis of Veno-Occlusive Complication in Allogeneiccit Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND

Hepatic veno-occlusive disease (VOD), also termed as sinusoidal obstruction syndrome (SOS), is a lethal complication after hematopoietic stem cell transplantation (HSCT). Various factors put patients undergoing allogeneic HSCT at an increased risk for VOD. Thrombomodulin (TM) is an important factor which has a wide range of effects, including anticoagulant, anti-inflammatory, angiogenic, and protective effect, on endothelial cells. It plays a role in preventing excessive coagulation and thrombosis by binding with thrombin and inhibiting the coagulation cascade. There are a limited number of options for the prevention of this fatal complication. Recombinant thrombomodulin (rTM), an endothelial anticoagulant co-factor, as prophylactic therapy might be able to prevent veno-occlusive complications after stem cell transplantation.

METHODS

A literature search was performed on PubMed, Embase, and Web of Science. We used the following Mesh terms and Emtree terms, "Hepatic Veno-Occlusive Diseases" OR "Sinusoidal Obstruction" OR "Stem Cell Transplantations " AND "Thrombomodulin" from the inception of data up to April 1, 2021. The PICO (Patient/Population, Intervention, Comparison and Outcomes) framework was used for the literature search.

RESULTS

For the VOD incidence after HSCTstem cell transplantation, the result was in favor of rTM with a risk ratio (RR) of 0.53 (I² = 0%, 95% confidence interval [CI] = 0.32-0.89). The incidence of transplant-associated thrombotic microangiopathy (TA-TMA) after HSCT was reduced in rTM group. The RR for incidence of TA-TMA was 0.48 (I² = 62%, 95% CI = 0.20-1.17) favoring rTM. The RR for incidence of graft-versus-host disease (GvHD) was also lower in rTM group, 0.48 (I² = 64%, 95% CI = 0.32-0.72).

CONCLUSION

In our meta-analysis, we evaluate the efficacy and safety of rTM in the prevention of SOS after HSCT. According to our results, rTM use led to a significant reduction in SOS episodes, TA-TMA, and GvHD after HSCT.

Endothelial Dysfunction after Hematopoietic Stem Cell Transplantation: A Review Based on Physiopathology

Endothelial dysfunction (ED) is frequently encountered in transplant medicine. ED is an argument of high complexity, and its understanding requires a wide spectrum of knowledge based on many fields of basic sciences such as molecular biology, immunology, and pathology. After hematopoietic stem cell transplantation (HSCT), ED participates in the pathogenesis of various complications such as sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD), graft-versus-host disease (GVHD), transplant-associated thrombotic microangiopathy (TA-TMA), idiopathic pneumonia syndrome (IPS), capillary leak syndrome (CLS), and engraftment syndrome (ES). In the first part of the present manuscript, we briefly review some biological aspects of factors involved in ED: adhesion molecules, cytokines, Toll-like receptors, complement, angiopoietin-1, angiopoietin-2, thrombomodulin, high-mobility group B-1 protein, nitric oxide, glycocalyx, coagulation cascade. In the second part, we review the abnormalities of these factors found in the ED complications associated with HSCT. In the third part, a review of agents used in the treatment of ED after HSCT is presented.

Genetic Predictors for Sinusoidal Obstruction Syndrome-A Systematic Review

Sinusoidal obstruction syndrome (SOS) is a potentially life-threatening complication after hematopoietic stem cell transplantation (HSCT) or antineoplastic treatment without HSCT. Genetic variants were investigated for their association with SOS, but the evidence is inconclusive. We performed a systematic literature review to identify genes, gene variants, and methods of association analyses of genetic markers with SOS. We identified 23 studies after HSCT and 4 studies after antineoplastic treatment without HSCT. One study (4%) performed whole-exome sequencing (WES) and replicated the analysis in an independent cohort, 26 used a candidate-gene approach. Three studies included >200 participants (11%), and six were of high quality (22%). Variants in 34 genes were tested in candidate gene studies after HSCT. Variants in GSTA1 were associated with SOS in three studies, MTHFR in two, and CPS1, CTH, CYP2B6, GSTM1, GSTP1, HFE, and HPSE in one study each. UGT2B10 and LNPK variants were identified in a WES analysis. After exposure to antineoplastic agents without HSCT, variants in six genes were tested and only GSTM1 was associated with SOS. There was a substantial heterogeneity of populations within and between studies. Future research should be based on sufficiently large homogenous samples, adjust for covariates, and replicate findings in independent cohorts.

Incidence, Predictors, and Outcomes of Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome after Reduced-Intensity Allogeneic Hematopoietic Cell Transplantation

fludarabine with intravenous busulfan at doses of 3.2 mg/kg (Flu/Bu1) or 6.4 mg/kg (Flu/Bu2). Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a serious complication of hematopoietic stem cell transplantation (HCT) that is felt to be triggered, at least in part, by damage to the liver sinusoidal endothelium from cytotoxic conditioning regimens. Accordingly, the incidence of VOD/SOS after reduced-intensity conditioning (RIC) HCT is low compared with myeloablative transplantation, and the natural history, risk factors, and outcomes of VOD/SOS after RIC have not been well characterized. We retrospectively reviewed 1583 consecutive patients receiving RIC HCT at the Dana-Farber Cancer Institute between 2007 and 2017 and ascertained 26 cases of VOD/SOS. The median day of VOD/SOS onset was 26 days (range, 5 to 48) and the cumulative incidence at day 50 was 1.6% (95% confidence interval [CI], 1.1% to 2.4%). Day 100 nonrelapse mortality rate was 23% in the VOD/SOS cohort compared with 6.4% in patients without VOD/SOS (P = .006). Cumulative incidence of VOD/SOS at day 50 was 3.1% after RIC regimen with Flu/Bu2 ± ATG (fludarabine with two doses of busulfan, total dose 6.4 mg/kg, with or without anti-thymocyte globulin), compared with 0.15% after Flu/Bu1 ± ATG (fludarabine with single busulfan dose 3.2 mg/kg, with or without anti-thymocyte globulin) (P = .0002); the incidence rate was 2.1% after RIC HCT with sirolimus-containing graft-versus-host disease prophylaxis, compared with 0.8% for RIC without sirolimus (P = .06). Significant risk factors identified in multivariable analysis for the development of VOD/SOS were sirolimus use (hazard ratio [HR], 5.1; 95% CI, 1.8 to 14.2; P = .002) and RIC regimen with Flu/Bu2 ± ATG (HR, 34; 95% CI, 4.5 to 252; P < .001) or other (HR, 32; 95% CI, 3.9 to 257; P = .001) compared with Flu/Bu1 ± ATG. Rising serum tacrolimus or sirolimus levels, new acute kidney injury, and increasing platelet transfusion requirements were significant early predictors of onset in the week preceding prior VOD/SOS diagnosis. When compared with a previously published cohort of 76 patients with VOD/SOS who developed VOD/SOS after myeloablative HCT in the same time period, VOD/SOS after RIC occurred later and was associated with a lower peak bilirubin level and better overall survival. The variability in presenting features for RIC VOD/SOS highlights the importance of maintaining a high index of suspicion for this entity in RIC HCT.

Drop of Butyrylcholinesterase Activity after Cyclophosphamide Conditioning as a Predictive Marker of Liver Transplant-Related Complications and Its Correlation with Transplant-Related Mortality in Pediatric Hematopoietic Stem Cell Recipients

Transplant-related liver complications are a potentially fatal condition of hematopoietic stem cell transplantation (HSCT) in pediatric patients, actually representing one of the main factors involved in transplant-related mortality (TRM). The search for a specific marker capable of predicting the development of this condition is a relevant clinical issue. We have observed a variable reduction in serum butyrylcholinesterase (BChE) activity after a cyclophosphamide-containing conditioning regimen. This study aims to determine the cutoff of BChE activity reduction that might be a specific prognostic marker for liver complications after HSCT. Our results show that the reduction of BChE values below 2000 U/L the day before the transplantation is an indicator strongly associated with the transplant-related liver complications (p < 0.0001). The incidence of overall survival at 1 year was significantly higher in the BChE > 2000 U/L group compared to the BChE < 2000 U/L group (84.7% versus 58.5%, p < 0.001), while the TRM rate was significantly lower (8.1% versus 23.1%, p < 0.05). None of the patients undergoing prophylaxis with defibrotide developed severe liver complications. Starting defibrotide treatment at the first signs of hepatic dysfunction in patients with particularly low BChE activity levels reduces severe liver transplant-related complications.

Fulminant hepatitis due to very severe sinusoidal obstruction syndrome (SOS/VOD) after autologous peripheral stem cell transplantation: a case report

BACKGROUND

Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (SOS/VOD), is a potentially fatal complication of allogeneic or autologous hematopoietic stem cell transplantation. A plethora of transplant and patient-related risk factors predispose to SOS/VOD and should be taken into account for prognosis assessment as well as for adequate therapeutic intervention.

CASE PRESENTATION

We describe the case of a mantle cell lymphoma patient who developed a fulminant hepatitis following oxaliplatin-containing intensive chemotherapy and autologous transplantation. This clinical manifestation was secondary to a very severe SOS/VOD. The patient did not exhibit the usual risk factors and presented a non-classical form with major cytolysis, thus puzzling SOS/VOD diagnosis in this context.

CONCLUSION

SOS has been previously reported after oxaliplatin-based chemotherapy regimens for colorectal cancers, in particular in patients with colorectal liver metastases. We therefore suspected a potential relationship with oxaliplatin-based regimen as a driver of SOS/VOD in a non-susceptible lymphoma patient. With regards to this case, clinicians and especially intensivists should be aware of this atypical presentation.

Cytoprotective and pro-angiogenic functions of thrombomodulin are preserved in the C loop of the fifth epidermal growth factor-like domain

We previously found that the fifth epidermal growth factor-like domain of thrombomodulin (TME5) exerts cytoprotective and pro-angiogenic functions via G-protein coupled receptor 15 (GPR15). TME5 is comprised of three S-S bonds that divide it into three loops: A (TME5A), B (TME5B), and C (TME5C). Herein we identified the minimum structure of TME5 that produces favorable effects in vascular endothelial cells (ECs). We found that TME5C, composed of 19 amino acids, but not TME5A or TME5B, stimulated the proliferation of human umbilical vein endothelial cells (HUVECs) and human hepatic sinusoidal endothelial cells (HHSECs). Matrigel plug assays showed that TME5C stimulates in vivo angiogenesis. In addition, TME5C counteracted calcineurin inhibitor-induced apoptosis and vascular permeability in HUVECs and HHSECs. Western blot analysis indicated that exposure of either HUVECs or HHSECs to TME5C increased the levels of anti-apoptotic myeloid cell leukemia-1 protein in association with the activation of signal transduction pathways, including extracellular signal-regulated kinase, AKT, and mitogen-activated protein kinase p38. Importantly, TME5C did not affect the coagulation pathway in vitro The cytoprotective function of TME5C was mediated by cell surface-expressed GPR15, as TME5C was not able to protect vascular ECs isolated from Gpr15 knock-out (KO) mice. Strikingly, TME5C successfully ameliorated sinusoidal obstruction syndrome in a murine model by counteracting the reduction of sinusoidal EC numbers. Taken together, the cytoprotective and pro-angiogenetic functions of TM are preserved in TME5C. The use of TME5C may be a promising treatment strategy to prevent or treat lethal complications, such as sinusoidal obstruction syndrome, whose pathogenesis is based on endothelial insults.

Evaluation of thromboelastometry parameters as predictive markers for sinusoidal obstruction syndrome in patients undergoing allogeneic stem cell transplantation for acute leukaemia

Hepatic sinusoidal obstruction syndrome (previously named veno-occlusive disease, SOS/VOD) is a serious complication of allogeneic stem cell transplantation (HSCT). Early identification of patients at risk of SOS/VOD may possibly improve the outcome and reduce mortality. Rotation thromboelastometry (ROTEM) is global assay allowing for the precise assessment of both bleeding and thrombotic conditions, however, its usefulness in patients undergoing HSCT for acute leukaemia has not been studied.

We evaluated the thromboelastometry parameters in patients undergoing allogeneic HSCT for acute leukaemia to identify candidate biomarkers of SOS/VOD occurrence.

ROTEM assays (INTEM, EXTEM, FIBTEM, APTEM) were performed on day -10, on the day of stem cell infusion (day 0) and on days +12 and +28 post-HSCT. The diagnosis of SOS/VOD was based on the Baltimore criteria. Seven patients (26%) developed SOS/VOD. On day +12, the patients with SOS/VOD had statistically significant longer INTEM-CT (clotting time, 199 ± 33.41vs166 ± 23.65s, p = 0.0033), EXTEM-CT (69.5 ± 6.39vs.52 ± 3.42s, p = 0.0139) and FIBTEM-CT (69.5 ± 22.75vs. 50.8 ± 14.31s, p = 0.0124) compared to SOS/VOD (-). ROC curve on day +12 indicated a cut-off value of 179s in INTEM-CT (AUC = 0.91), 69s in EXTEM-CT (AUC = 0.90) and 102s in FIBTEM-CT (AUC = 0.82) for the prediction of SOS/VOD.

This is the first study evaluating the usefulness of ROTEM assays in the early detection of haemostasis abnormalities predictive of SOS/VOD development in patients undergoing HSCT for acute leukemia. Patients with SOS/VOD had a significant delay in the initiation of thrombin formation in the analysed ROTEM assays. The utility of ROTEM assays in the optimal management of patients undergoing HSCT should be clarified in further prospective studies.

Defibrotide in the treatment of hepatic veno-occlusive disease

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), represents the most frequent complication in patients in early phase following hematopoietic stem-cell transplantation (HSCT). In its severe form, VOD/SOS can be associated with multiorgan failure and with a mortality rate >80% by day +100. Defibrotide (DF) (a mixture of 90% single-stranded phosphodiester oligonucleotides and 10% double-stranded phosphodiester oligonucleotides derived from controlled depolarization of porcine intestinal mucosal DNA) has been proposed for the treatment of SOS due to its ability to restore thrombo-fibrinolytic balance and protect endothelial cells. The present review highlights why the mechanisms of action of DF allow its successful use in the prevention and treatment of SOS following HSCT.

Chlorogenic acid suppresses monocrotaline-induced sinusoidal obstruction syndrome: The potential contribution of NFκB, Egr1, Nrf2, MAPKs and PI3K signals

Hepatic sinusoidal obstruction syndrome (SOS) is a highly lethal liver disease. This study aims to observe the protection and its engaged mechanism of chlorogenic acid (CGA) against monocrotaline (MCT)-induced SOS. Results of detecting liver ascites, measuring serum transaminases, liver histological evaluation and scanning electron microscope observation all demonstrated that CGA prevented MCT-induced SOS in rats. CGA reduced MCT-induced increased liver myeloperoxidase (MPO) activity, tumor necrosis factor (TNF)α and interleukin (IL)-1β mRNA expression, toll-like receptor (TLR)-2,3,6,9 expression, and nuclear factor κB (NFκB) transcriptional activation. CGA also decreased MCT-induced early growth response1 (Egr1) activation. CGA reduced MCT-induced elevated liver malondialdehyde (MDA) amount and enhanced nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). CGA blocked MCT-induced PI3K and MAPKs activation. In conclusion, this study demonstrates the protection of CGA against MCT-induced SOS. Transcriptional factor NFκB, Egr1 and Nrf2-regulated inflammation, coagulation-fibrinolysis, and antioxidant, and PI3K and MAPKs all contribute to such protection.

Safety of peritoneal and pleural drain placement in pediatric stem cell transplant recipients with severe veno-occlusive disease

Hepatic VOD (veno-occlusive disease) is a serious complication of HSCT (hematopoietic stem cell transplantation) and has historically been associated with high mortality. This obstruction to hepatic flow often results in fluid collections in the peritoneal and pleural cavities. Catheter placement to drain ascites or pleural fluid may reduce intra-abdominal hypertension and/or improve respiratory parameters. The safety of these interventions among critically ill, immunocompromised children is unknown. Among 32 HSCT recipients (2000-2012) with severe VOD, we assessed the primary outcome of procedural complication from peritoneal drain placement. Twenty-four (75%) patients underwent peritoneal drain placement. No patient sustained visceral perforation or hemorrhage with drain placement. Overall mortality was 47% (n = 15). The procedure was not associated with increased overall mortality (p > 0.99). Eight (25%) peritoneal drains required replacement for malfunction. Of 24 patients with peritoneal drains, one (4%) patient had a positive culture from ascitic fluid. Eight (25%) patients underwent pleural drain placement. No pleural drain-related procedural complication or infection occurred. Four (50%) of the eight patients with pleural drains had de-escalation in oxygen requirement at drain removal, compared to time of placement. In this study, peritoneal and pleural drains were safe interventions for children with severe VOD.

Hemostatic Abnormalities and Changes Following Bone Marrow Transplantation

Hemostatic parameters were examined in 39 patients who underwent allogeneic bone marrow transplantation (BMT). Twenty-six patients survived and 13 patients died within 6 months after BMT. The main causes of death were acute graft-versus-host disease (GVHD: n=6), veno-occlusive disease (VOD: n=2), and thrombotic microangiopathy (TMA: n=2). Plasma levels of D-dimer and thrombomodulin (TM) were significantly elevated in the non-survivor group. Plasma levels of soluble fibrin (SF) and Fas were significantly elevated in the non-survivor group at 1 to 4 weeks after BMT. Plasma levels of thrombin-antithrombin complex (TAT), D-dimer, and tissue plasminogen activator-plasminogen activator inhibitor-1 complex (tPA-PAI-1 complex) were significantly elevated in patients with complications after BMT. Plasma levels of TAT, D-dimer, and tPA-PAI-1 complex were significantly elevated in patients with GVHD. These results suggest that abnormalities of hemostatic parameters might predict poor outcomes or complications in patients with BMT.

Revised diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients: a new classification from the European Society for Blood and Marrow Transplantation

Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life threatening complication that can develop after hematopoietic cell transplantation. Although SOS/VOD progressively resolves within a few weeks in most patients, the most severe forms result in multi-organ dysfunction and are associated with a high mortality rate (>80%). Therefore, careful attention must be paid to allow an early detection of SOS/VOD, particularly as drugs have now proven to be effective and licensed for its treatment. Unfortunately, current criteria lack sensitivity and specificity, making early identification and severity assessment of SOS/VOD difficult. The aim of this work is to propose a new definition for diagnosis, and a severity-grading system for SOS/VOD in adult patients, on behalf of the European Society for Blood and Marrow Transplantation.

Antineoplastic agent busulfan regulates a network of genes related to coagulation and fibrinolysis

Purpose Hepatic veno-occlusive disease (HVOD) is one of the major complications following hematopoietic stem cell transplantation (HSCT). Although high-dose busulfan is associated with the development of HVOD, the underlying molecular mechanisms are still unknown.Methods Transcriptional gene regulation by busulfan was profiled using Affymetrix GeneChip® Human Genome U133 Plus 2.0 arrays. Messenger RNA (mRNA) expression of regulated genes was assessed by TaqMan real-time polymerase chain reaction (PCR), and protein expression and secretion was determined by enzyme-linked immunosorbent assay (ELISA)in cell supernatants, lysates, and patient plasma.Results Plasma levels of plasminogen activator inhibitor(PAI)-1 significantly increased 48 h after starting busulfan treatment IV in children preconditioned for HSCT. In vitro,busulfan significantly induced plasminogen activator inhibitor-1 (PAI-1) expression in endothelium-like ECV304 cells in a concentration- and time-dependent manner. Comparative transcriptional profiling of busulfan-treated and control ECV304 cells identified differential expression of genes related to coagulation and fibrinolysis, including tissue factor, tissue factor pathway inhibitor-1, protein S, thrombospondin-1, urokinase receptor, and PAI-1, as well as activin A and transforming growth factor beta 1 (TGF-β1). Ingenuity pathway analysis (IPA) suggested TGF-β1 as a central modulator of gene regulation by busulfan. Consequently, expression of tissue factor, urokinase receptor, and PAI-1 mRNA and PAI-1 protein secretion induced by busulfan were significantly reduced by the activin A/TGF-β1 inhibitor SB 431542 in ECV304 and primary endothelial cells.Conclusions This is the first report that directly relates busulfan exposure to antifibrinolytic activity by PAI-1 and hypercoagulation possibly mediated by members of the TGF-β1 family. This suggests further research to evaluate activin A and TGF-β1 as potential targets for HVOD treatment.

Contribution of fibrinolytic tests to the differential diagnosis of veno-occlusive disease complicating pediatric hematopoietic stem cell transplantation

BACKGROUND

Veno-occlusive disease (VOD) is a major complication following hematopoietic stem cell transplantation (HSCT). Its diagnosis is based on clinical criteria, which have a limited sensitivity. Increased plasminogen activator inhibitor-1 (PAI-1) levels have been suggested as a marker of VOD. We aimed to prospectively evaluate how the fibrinolytic parameters behaved to discriminate VOD from other liver disorders occurring after HSCT in a pediatric population.

PROCEDURES

A total of 195 HSCT were performed on 161 children and VOD complicated 11 cases (6.8%). Alanine aminotransferase, total bilirubin, PAI-1 antigen (PAI-1:Ag) and activity, t-PA antigen, D-dimer, prothrombin time, activated partial thromboplastin time, antithrombin, fibrinogen, and platelet counts were measured in 105 HSCT before and then weekly for 1 month after HSCT.

RESULTS

An early, significant increase in the fibrinolytic parameters was seen in patients who developed VOD, even before VOD was diagnosed clinically, by comparison with patients without complications or those with non-VOD liver disorders. The combined increase in bilirubin, D-dimer, and PAI-1:Ag levels beyond the normal range distinguished VOD cases from other liver complications with a high sensitivity and specificity.

CONCLUSIONS

Our study demonstrates that fibrinolytic tests can help diagnose VOD after HSCT in the pediatric population.

Hepatic radiation toxicity: avoidance and amelioration

The refinement of radiation therapy and radioembolization techniques has led to a resurgent interest in radiation-induced liver disease (RILD). The awareness of technical and clinical parameters that influence the chance of RILD is important to guide patient selection and toxicity minimization strategies. "Classic" RILD is characterized by anicteric ascites and hepatomegaly and is unlikely to occur after a mean liver dose of approximately 30 Gy in conventional fractionation. By maintaining a low mean liver dose and sparing a "critical volume" of liver from radiation, stereotactic delivery techniques allow for the safe administration of higher tumor doses. Caution must be exercised for patients with hepatocellular carcinoma or pre-existing liver disease (eg, Child-Pugh score of B or C) because they are more susceptible to RILD that can manifest in a nonclassic pattern. Although no pharmacologic interventions have yet been proven to mitigate RILD, preclinical research shows the potential for therapies targeting transforming growth factor-β and for the transplantation of stem cells, hepatocytes, and liver progenitor cells as strategies that may restore liver function. Also, in the clinical setting of veno-occlusive liver disease after high-dose chemotherapy, agents with fibrinolytic and antithrombotic properties can reverse liver failure, suggesting a possible role in the setting of RILD.

Decreased activity of soluble thrombomodulin and plasma procoagulant phospholipids in childhood bone marrow transplantation with severe complications

BACKGROUND

Complications of bone marrow transplantation (BMT) are usually considered to be related to the secretion of inflammatory cytokines, which generate membrane microparticles rich in procoagulant phospholipids (PPL) from different cellular origins and release of endothelial proteins such as thrombomodulin (TM). The use of soluble TM quantified by ELISA (TM:Ag) as a marker of endothelial injury is complex in children since it is age-dependent.

MATERIALS AND METHODS

Using a functional assay which quantifies the activity of sTM activity (TMa), we performed a pilot study to analyze the ratio TMa/TM:Ag in a control group of 25 healthy children, 8 children with autologous and 16 children with allogeneic BMT. In this last group, 8 experienced BMT complications. In addition, we used a functional assay which quantifies PPL.

RESULTS

In healthy children the ratio TMa/TM:Ag was independent of age and stable in children with a favorable outcome but significantly (p<0.05) reduced by the use of antithymocyte globulin during the conditioning regimen, and regularly decreased in children with BMT complications. Surprisingly, low plasma PPL levels were associated with a poor outcome.

CONCLUSION

The ratio TMa/TM:Ag could constitute a marker of endothelium injury, and its follow-up could be of interest for an early discrimination of children with high risk of complications during allogeneic BMT. The decrease of PPL could be also another marker of a poor evolution and deserves further investigations.

Use of defibrotide in the treatment and prevention of veno-occlusive disease

Hepatic veno-occlusive disease (VOD) is one of the most important complications of high-dose chemotherapy and stem cell transplantation. VOD is a clinical syndrome characterized by jaundice, hepatic enlargement and fluid retention typically seen by day +30 after transplantation. Severe VOD is complicated by multiorgan failure and a high mortality rate approaching 100%. Defibrotide (DF) is a novel agent with both antithrombotic and fibrinolytic properties that has emerged as an effective therapy for severe VOD. In Phase II studies, treatment of severe VOD has resulted in complete responses of 30-60% and survival past day 100 ranging between 32-50%. A Phase III, historically controlled study of DF for treatment of severe VOD has recently been completed and results are awaited with interest. In addition, DF may be effective prophylaxis for VOD in high-risk patients. This review will focus on a summary of the pharmacology of DF and the clinical evidence for its use in VOD.

Prediction of veno-occlusive disease using biomarkers of endothelial injury

Predicting the development of veno-occlusive disease (VOD) of the liver remains challenging. We hypothesized that biomarkers of endothelial injury in myeloablative allogeneic transplantation recipients could predict VOD occurrence. We evaluated 4 biomarkers-von Willebrand Factor (vWF), thrombomodulin, E-selectin, and soluble intercellular adhesion molecule-1 (sICAM-1)-weekly in the peritransplantation period in an attempt to predict VOD. In the patients who received sirolimus, vWF, thrombomodulin, and sICAM-1 levels were significantly elevated in patients with VOD compared with those without VOD on day -1 (P <or= .035), day +7 (P <or= .0001), and day +14 (P <or= .004). E-selectin was predictive on day +7 (P = .007). Levels of vWF >or=1400 IU/mL and thrombomodulin >or=100 ng/mL on day +7 were both 100% sensitive and 100% specific in predicting VOD. These biomarkers were informative when adjusted for other risk factors for VOD in regression analysis. Among patients not receiving sirolimus, biomarkers of endothelial injury were not informative. We conclude that vWF, thrombomodulin, and sICAM-1 elevations before and early after transplantation may be useful in predicting VOD in patients receiving sirolimus.

Hepatic veno-occlusive disease following stem cell transplantation: incidence, clinical course, and outcome

The occurrence of hepatic veno-occlusive disease (VOD) has been reported in up to 60% of patients following stem cell transplantation (SCT), with incidence varying widely between studies depending on the type of transplant, conditioning regimen, and criteria used to make the diagnosis. Severe VOD is characterized by high mortality and progression to multiorgan failure (MOF); however, there is no consensus on how to evaluate severity. This review and analysis of published reports attempts to clarify these issues by calculating the overall mean incidence of VOD and mortality from severe VOD, examining the effect of changes in SCT practice on the incidence of VOD over time, and discussing the methods used to evaluate severity. Across 135 studies performed between 1979 and October 2007, the overall mean incidence of VOD was 13.7% (95% confidence interval [CI]=13.3%-14.1%). The mean incidence of VOD was significantly lower between 1979-1994 than between 1994-2007 (11.5% [95% CI, 10.9%-12.1%] vs 14.6% [95% CI, 14.0%-15.2%]; P <.05). The mortality rate from severe VOD was 84.3% (95% CI, 79.6%-88.9%); most of these patients had MOF, which also was the most frequent cause of death. Thus, VOD is less common than early reports suggested, but the current incidence appears to be relatively stable despite recent advances in SCT, including the advent of reduced-intensity conditioning. The evolution of MOF in the setting of VOD after SCT can be considered a reliable indication of severity and a predictor of poor outcome.

Relation of Soluble Endothelial Protein C Receptor and Cytokines After Allogeneic Hematopoietic Stem Cell Transplantation

Aim: The objective of this study was to elucidate the effects of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 2 (IL-2), interleukin 6 (IL-6), and interleukin 8 (IL-8) on the expression of soluble endothelial protein C receptor (sEPCR) in the pathogenesis of thrombotic complications after hematopoietic stem cell transplantation (HSCT).

Methods: The relationship between plasma concentrations of proinflammatory cytokines (TNF-α, IL-1β, IL-2, IL-6, and IL-8) and sEPCR was evaluated in 32 consecutive allogeneic hematopoietic stem cell—transplanted patients prior to conditioning regimen and randomly once between +5 and +30 days after transplantation and compared these results with 20 healthy controls.

Results: Soluble endothelial protein C receptor levels did not indicate any significant difference between pre- and posttransplantation period, and sEPCR levels showed a significantly negative correlation between IL-6 and IL-8 (sEPCR and IL-6, r = —.43, P < .01; sEPCR and IL-8, r = —.57, P < .01). There was no correlation between sEPCR levels and TNF-α, IL-1β, or IL-2 (sEPCR and TNF-α, r = —.13, P > .05; sEPCR and IL-1β, r = —.1, P ≥ .05; sEPCR and IL-2, r = —.07, P > .05).

Conclusions: Our results suggest that the production of sEPCR was not affected by allogeneic HSCT. Soluble endothelial protein C receptor did not show any positive correlation between these proinflammatory cytokines (TNF-α, IL-1β, IL-2, IL-6, and IL-8), on the contrary a significantly negative correlation was determined between sEPCR and either IL-6 or IL-8. This negative correlation may be a protective mechanism in the pathway of protein C activation.

Early intervention with antithrombin III therapy to prevent progression of hepatic venoocclusive disease

Venoocclusive disease (VOD) is the most frequent cause of early nonrelapse mortality among patients receiving high-dose chemoradiotherapy and hematopoietic stem cell transplantation. Endothelial injury of sinusoids and hepatic veins following chemotherapy is considered the initial event in the development of VOD. Activation of the coagulation cascade and inflammatory processes following endothelial injury results in a hypercoagulable state and a localized consumption of the natural anticoagulants, antithrombin III, protein C and protein S. The resultant coagulopathy can lead to multiorgan dysfunction and death. The objective was to retrospectively study the largest series of patients that has received antithrombin III for the treatment of VOD following hematopoietic stem cell transplantation. A total of 48 patients were diagnosed with VOD post hematopoietic stem cell transplantation (median age, 39 years; range, 1-69 years); 38 of the 48 received a nonradiation-based conditioning regimen and 21 of 48 received a transplant from an unrelated donor. Treatment was primarily directed at early intervention rather than prophylactic therapy to correct the antithrombin III deficiency associated with VOD. We attempted to achieve antithrombin III levels greater than 120%. There was no significant treatment-related morbidity. The overall 100-day mortality for the treatment cohort was 17%, with 10% for the mild/moderate group and 39% for the severe group, respectively. In conclusion, the encouraging results of this study suggest that this antithrombin III treatment should be further considered in patients with severe VOD.

Toxicity and efficacy of 6-thioguanine versus 6-mercaptopurine in childhood lymphoblastic leukaemia: a randomised trial

BACKGROUND

6-mercaptopurine has been a standard component of long-term continuing treatment for childhood lymphoblastic leukaemia, whereas 6-thioguanine has been mainly used for intensification courses. Since preliminary data have shown that 6-thioguanine is more effective than 6-mercaptopurine, we compared the efficacy and toxicity of the two drugs for childhood lymphoblastic leukaemia.

METHODS

Consecutive children with lymphoblastic leukaemia diagnosed in the UK and Ireland between April, 1997, and June, 2002, were randomly assigned either 6-thioguanine (750 patients) or 6-mercaptopurine (748 patients) during interim maintenance and continuing therapy. All patients received 6-thioguanine during intensification courses. We analysed event-free and overall survival on an intention-to-treat basis. We obtained toxicity data using an adverse-event reporting system, with follow-up questionnaires to seek detailed information for specific toxicities. This trial is registered with the International Standard Randomised Controlled Number 26727615 with the name ALL97.

FINDINGS

After a median follow up of 6 years, there was no difference in event-free or overall survival between the two treatment groups. Although 6-thioguanine conferred a significantly lower risk of isolated CNS relapse than did 6-mercaptopurine (odds ratio [OR] 0.53, 95% CI 0.30-0.92, p=0.02), the benefit was offset by an increased risk of death in remission (2.22, 1.20-4.14, p=0.01), mainly due to infections during continuing therapy. Additionally, 95 patients developed veno-occlusive disease of the liver. Of these, 82 were randomly assigned 6-thioguanine, representing 11% of all 6-thioguanine recipients. On long-term follow-up, about 5% of 6-thioguanine recipients have evidence of non-cirrhotic portal hypertension due to periportal liver fibrosis or nodular regenerative hyperplasia.

INTERPRETATION

Compared with 6-mercaptopurine, 6-thioguanine causes excess toxicity without an overall benefit. 6-mercaptopurine should remain the thiopurine of choice for continuing therapy of childhood lymphoblastic leukaemia.

Unchanged global fibrinolytic capacity during the course of hematopoietic stem cell transplantation

Hemostatic changes due to vascular endothelial damage are seen during the course of hematopoietic stem cell transplantation (HSCT). The fibrinolytic response to ongoing hemostatic activation in HSCT remains to be elucidated. Global fibrinolytic capacity (GFC) is a novel method, which reflects the amount of generated D-dimer when fibrinolysis of a freeze-dried fibrin clot is stopped by introducing aprotinin. GFC is sensitive to all the factors involved in the process of fibrinolysis. The aim of this study was to serially assess GFC at certain critical time points (days -1, +7, +14, +21 prior to and following stem cell infusion) during the course of HSCT. The study group comprised 16 patients with hematological malignancies (11 women, five men; median age 32+/-9 years) in whom HSCT had been performed. Thirty healthy adults (21 women, nine men; median age 31+/-7 years) served as controls. In this study, global fibrinolytic response, as reflected by GFC, was unchanged despite ongoing hemostatic activation, as indicated by D-dimer, moreover GFC remained stable, despite the development of thrombocytopenia associated with HSCT prior to platelet engraftment. Our results indicate that a global fibrinolytic response was impaired as a compensatory response to endothelial activation and to other hemostatic changes seen in HSCT. Further studies in larger HSCT populations are warranted to better understand the implications of these findings.

Diagnosis of Hepatic Veno-occlusive Disease by Plasminogen Activator Inhibitor-1 Plasma Antigen Levels: A Prospective Analysis in 350 Allogeneic Hematopoietic Stem Cell Recipients

BACKGROUND

Veno-occlusive disease (VOD) is one of the most serious complications following allogeneic hematopoietic stem cell transplantation (HSCT) and is associated with a high mortality. We conducted a large trial in order to investigate the value of plasminogen activator inhibitor-1 (PAI-1) plasma antigen levels in VOD patients as PAI-1 has been described as a possible diagnostic marker of VOD.

METHODS

In all, 350 stem cell recipients were included in our study. PAI-1 levels were analyzed prior to conditioning therapy and then weekly until eight weeks after HSCT. Transplantation-related complications (TRC) including VOD, microangiopathic hemolytic anemia (MAHA), and graft-versus-host disease (GVHD) were recorded weekly throughout the study.

RESULTS

Maximum PAI-1 antigen levels were increased in all patients with VOD (n=15; mean 248 ng/ml; 95% CI 183-314 ng/ml). Maximum PAI-1 levels above 120 ng/ml showed a sensitivity of 100% and a specificity of 30.6% for VOD after HSCT.

CONCLUSION

Our study underlines that maximum PAI-1 plasma antigen levels not exceeding 120 ng/ml have a strong negative predictive value in the diagnosis of VOD and thus represent a helpful non-invasive tool for exclusion of VOD after HSCT.

Protein C and procollagen III peptide levels in patients with hepatic dysfunction after allogeneic hematopoietic stem cell transplantation

Veno-occlusive disease (VOD) is one of the most serious complications following hematopoietic stem cell transplantation (HSCT) and is associated with a high mortality. We conducted a large trial on the clinical significance of protein C (PC) and procollagen III peptide (PNPIII) levels, which have been described as possible diagnostic markers of VOD. In total, 350 patients undergoing allogeneic HSCT were included. PC and PNPIII levels were analyzed prior to conditioning and weekly until 8 weeks after the HSCT. Signs of VOD and other transplantation-related complications (graft-versus-host disease (GVHD), toxicity, microangiopathic hemolytic anemia, infection) were recorded weekly throughout the trial. Patients showed a significant drop of the PC levels in VOD (70.3 vs 96.3%, P<0.001) and with increasing severity of aGVHD. Steroids increased the PC levels (69.4% vs 109.4%, P<0.001). The highest PNPIII levels were registered in patients with VOD (mean 6.3 IU/ml). Patients with aGVHD showed an elevation of PNPIII, especially patients with hepatic aGVHD. PC levels during conditioning do not predict VOD (98.5 vs 76.5%, NS). Although PC and PNPIII may play a role in the pathogenesis of VOD they cannot discriminate between complications with jaundice and are only of limited help in the differential diagnosis of VOD.

Hepatic veno-occlusive disease: pathogenesis, diagnosis and treatment

Hepatic veno-occlusive disease (VOD) is one of the most serious complications following hematopoietic stem cell transplantation (SCT) and is associated with a very high mortality in its severe form. This review outlines the pathogenesis and clinical features of VOD, with an emphasis on endothelial cell injury and risk factors. The current status and future directions of research for both prophylaxis and treatment are also discussed.

Homocysteine and prothrombin fragment 1+2 levels in patients with veno-occlusive disease after stem cell transplantation

Veno-occlusive disease (VOD) of the liver remains a major complication after hematopoietic stem cell transplantation (SCT). VOD is thought to develop after hepatic endothelial cells are damaged by high-dose chemotherapy or radiation, causing microthrombosis in hepatic venules. However, the precise mechanisms leading to VOD are not well defined, and a diagnosis is often difficult to establish. It is also difficult to predict which patients are most likely to develop VOD. Elevated levels of homocysteine (HC) have been associated with thrombosis, and prothrombin fragment 1 + 2 (F1 + 2) is a measurable marker for coagulation. Therefore, we performed a prospective cohort study to determine if HC or F1 + 2 levels could be used to predict the development of VOD prior to SCT, or to help establish a diagnosis of VOD in association with other clinical parameters. Plasma levels of these factors were measured before conditioning and serially for 21 days after SCT in 42 consecutive patients undergoing SCT. Eleven of 26 allogeneic SCT recipients developed VOD, whereas no autologous SCT recipient (n = 16) developed VOD (p = 0.008). In patients who developed VOD, HC levels were consistently higher than those seen in non-VOD patients after day 7 of SCT. Patients with VOD also had higher levels of F1 + 2 after SCT, although this marker was less consistently elevated over time. A logistic regression model that evaluated all serial measures of HC and F1 + 2 showed a moderate sensitivity and specificity in diagnosing VOD in allogeneic SCT patients, but neither marker was useful to predict development of VOD when tested prior to SCT.

Markers of endothelial function in pediatric stem cell transplantation for acute leukemia

BACKGROUND

Endothelial cells and leukocytes intimately interact in inflammation and coagulation processes, so that dysregulation of their function may lead to both cellular damage and thrombosis, which may occur as complications of bone marrow transplantation (BMT). Partially conflicting evidence about endothelial markers and their relationships with clinical complications after BMT has been reported in the literature. Since almost all studies were carried out in adults, we evaluated some recent available markers of endothelial cell function in pediatric patients undergoing stem cell transplantation (SCT) for acute leukemia.

PROCEDURE

We studied the variation in circulating serum endothelial-selectin (ES), leukocyte-selectin (LS), thrombomodulin (TM), von Willebrand factor (vWF), nitrate + nitrite (NO(2) (-)/NO(3) (-)), endothelin-1 (EN), and tissue factor (TF) in 21 pediatric patients undergoing SCT for acute leukemia.

RESULTS

ES and LS significantly lowered following SCT and returned to pre-SCT levels 4 weeks after the procedure. NO(2) (-)/NO(3) (-) markedly increased following SCT. Also, TM and vWF increased, although such changes did not reach statistical significance. EN and TF did not appreciably change. A strong correlation was observed between white blood cell (WBC) count and both ES and LS, as well as between such selectins. TM significantly correlated with both selectins and NO(2) (-)/NO(3) (-). The pre-conditioning levels of TM and vWF in patients undergoing major complications, considered altogether, were significantly lower and higher, respectively, than in uncomplicated patients. NO(2) (-)/NO(3) (-) levels 3 and 4 weeks post-SCT were significantly lower in patients suffering from veno occlusive disease. Both selectins were significantly higher in allo- than in auto-transplanted patients 4 weeks after SCT.

CONCLUSIONS

Our data support the hypothesis of severe endothelial damage after conditioning and SCT, particularly allogeneic. However, the increase in TM, which has strong anticoagulant properties, and metabolites of NO, involved also in protective actions, may reflect regeneration of the anti-thrombotic endothelial function. This could take place after transitory functional impairment, rather than pure endothelial damage.

Plasminogen activator inhibitor-1 is an independent diagnostic marker as well as severity predictor of hepatic veno-occlusive disease after allogeneic bone marrow transplantation in adults conditioned with busulphan and cyclophosphamide

We attempted to identify the diagnostic markers and severity predictors of hepatic veno-occlusive disease (VOD) in 115 adult patients who were uniformly conditioned with busulphan and cyclophosphamide and who underwent allogeneic bone marrow transplantation (BMT). A diagnosis of VOD was made according to clinical criteria. Severity of VOD was classified as mild, moderate or severe. Various haemostatic parameters were determined at five time points (d -7, 0, 7, 14 and 21). Using clinical and haemostatic parameters, we developed multivariate models to identify diagnostic markers as well as severity predictors of VOD. Of the 115 patients included in the study, 50 (43.5%) developed VOD. Twenty-nine had mild VOD, 13 moderate and 8 severe. Multiple logistic regression models showed that plasminogen activator inhibitor-1 (PAI-1) antigen (P = 0.029), percentage change of body weight (P = 0.001) and bilirubin (P < 0.001) were independent marker variables for the occurrence of VOD, and PAI-1 antigen (P = 0.030) and bilirubin (P = 0.049) were independent marker variables for the occurrence of severe VOD. Our study suggests that PAI-1 antigen can be used as a diagnostic marker as well as a severity predictor of VOD after allogeneic BMT.

Impaired activity of plasma von Willebrand factor-cleaving protease may predict the occurrence of hepatic veno-occlusive disease after stem cell transplantation

Hepatic veno-occlusive disease (VOD) is a life-threatening complication after stem cell transplantation (SCT), characterized by thrombus formation in hepatic venules leading to a symptom triad of hyperbilirubinemia, hepatomegaly, and ascites. Multifactorial defects in the hemostatic system may contribute to its pathogenesis, but its remains to be investigated. Unusually large VWF multimers (UL-VWFMs), produced in and released from vascular endothelial cells, are most biologically active in the interaction with platelets under a high shear stress. UL-VWFMs are cleaved and degraded into smaller VWFMs by a specific liver producing plasma protease, termed VWF-cleaving protease (VWF-CPase), which has recently been identified as a metalloprotease solely produced in liver, termed ADAMTS13. Herein, we studied the correlation between plasma VWF-CPase activity and UL-VWFMs in 21 patients who received SCT, seven patients with VOD and 14 patients without VOD. In non-VOD patients, activities (mean +/- 1s.d.) of VWF-CPase were 78 +/- 17% of the control before the conditioning regimen, 76 +/- 18% on day 0, 64 +/- 19% on day 7, 57 +/- 23% on day 14, 68 +/- 13% on day 21 and 79 +/- 19% on day 28 after SCT. The respective values in VOD patients were 32 +/- 19%, 27 +/- 15%, 18 +/- 11%, 22 +/- 18%, 26 +/- 22% and 12 +/- 4%. Thus, VWF-CPase activity was significantly reduced in VOD patients, even before the conditioning regimen, and such a difference was not found in other laboratory tests. However, despite such a clear difference, UL-VWFMs were present in plasmas of both patient groups, together with the increase of VWF antigen and ristocetin cofactor activity. These results indicate that the measurement of this enzyme activity is extremely useful in predicting the occurrence of VOD prior to a demonstration of its direct involvement in its pathogenesis.

Hemostatic abnormalities following bone marrow transplantation

Hemostatic abnormalities in 26 patients following bone marrow transplantation (BMT) were examined. In the event-free survival group, the plasma levels of antithrombin (AT) and protein C (PC) were significantly decreased 1 and 2 weeks after BMT, and the plasma levels of thrombomodulin (TM) and tissue plasminogen activator-plasminogen activator inhibitor-1 complex (tPA-PAI-I complex) were significantly increased from 4 weeks to 13 weeks after BMT. Excepting AT, there was no significant difference in hemostatic parameters before BMT among the event-free survival, 6-month survival, and death within 6 months groups. On day 0 following BMT, only plasma AT levels were significantly lower in the 6-month survival group than in the death within 6 months group. From 1 to 3 weeks after BMT, plasma levels of AT or PC were significantly lower in the death within 6 months group than in the 6-month survival group. From 1 to 5 weeks after BMT, the plasma levels of TM and tissue type plasminogen activator-plasminogen activator inhibitor-I complex (tPA-PAI-I complex) were significantly higher in the 6-month survival group than in the death within 6 months group. From 1 to 13 weeks after BMT, the plasma levels of D-dimer or soluble fibrin monomer (SFM) were significantly higher in the death within 6 months group than in the 6-month survival group. There was no remarkable difference in plasma levels of thrombin-antithrombin comlex or plasmin-plasmin inhibitor complex following BMT between these groups of patients. These findings suggest that the decrease in the plasma AT or PC level reflects early occurrence of complications of prognostic significance and that the increase in vascular endothelial cell markers such as plasma levels of TM or tPA-PAI-I complex reflects occurrence of complications during the middle course of BMT. Plasma levels of D-dimer and SFM may be useful markers for predicting complications associated with poor prognosis after BMT.

Acquired factor VII deficiency in hematopoietic stem cell transplant recipients

Acquired factor VII (FVII) deficiency in the absence of vitamin K deficiency, oral anticoagulant therapy, synthetic liver dysfunction, or DIC is rare, with only a handful of cases thus far reported. In the period from 1990 to 1996 we identified eight patients with acquired FVII deficiency, all of whom presented with prolongation of the prothrombin time (PT) in the first 2 weeks following stem cell transplantation (SCT). The mean plasma FVII clotting activity (FVII:c) was 22% (range 8-35%) with an approximately equivalent reduction in FVII antigen (FVII:Ag) level. Mean plasma levels of fibrinogen and factors II, V, IX, and X were normal. Protein C activity was significantly depressed in only one of the three patients in whom it was measured. Several patients experienced bleeding complications, and hemorrhage directly accounted for death in two cases. Veno-occlusive disease of the liver developed in three patients. We conclude that FVII deficiency should be considered in the differential diagnosis of prolonged PT in patients who have recently undergone SCT. The mechanism of this acquired deficiency state remains to be defined.

Noncirrhotic portal hypertension

Noncirrhotic portal hypertension represents a heterogeneous group of conditions that have distinct clinical and hemodynamic features that often help distinguish them from cirrhosis. [figure: see text] The sites of portal flow resistance may not be precisely localized to one area of the hepatic lobule and may extend beyond the site where the pathogenetic process began. Even in patients with portal hypertension caused by an increased flow, there may be subsequent development of increased resistance. The prognosis is variable; outcomes are better in patients with presinusoidal portal hypertension. A good understanding of the presentation of the various noncirrhotic conditions that cause portal hypertension will help determine the cause, the site of resistance, and the therapeutic plan. Ascites is not a feature of presinusoidal portal hypertension, whereas it may be the predominant feature in postsinusoidal portal hypertension.

Predictive markers for hepatic veno-occlusive disease after hematopoietic stem cell transplantation in adults: a prospective single center study

Hepatic veno-occlusive disease (VOD) is a major complication after hematopoietic stem cell transplantation (HSCT). Aetiological determinants, diagnosis and treatment remain unclear. Changes in coagulation-fibrinolysis parameters and N-terminal propeptide for type III procollagen (P-III-P) have been studied in patients with or without VOD after HSCT. We prospectively measured protein C activity, tissue plasminogen activator (t-PA), antithrombin III (AT-III), plasminogen activity (PLG), thrombin-antithrombin III (TAT), alpha2-plasmin inhibitor (alpha2-PI),fibrinogen (Fbg) and P-III-P in 44 consecutive adult patients undergoing allogeneic HSCT. Each parameter was determined before conditioning, on day 0 of HSCT and weekly for 5 weeks. Five of the 44 patients developed VOD at a median post HSCT of day 3 (range, day 3 to 12). On repeated analysis of variance (ANOVA), there were significant differences between patients with and without VOD in P-III-P (P < 0.0001), protein C (P < 0.0001), t-PA (P < 0.0001), PLG (P < 0.0001), AT-III(P < 0.0001), Fbg (P < 0.0001), alpha2-PI (P = 0.0002). Levels of P-III-P were significantly higher in patients with VOD than without VOD, before preparative chemotherapy (P < 0.005) and on days 0 and 7 (P < 0.001). On day 0, levels of t-PA were significantly higher in patients with VOD than without VOD (P < 0.05). On day 7, levels of protein C were significantly lower in patients with VOD than without VOD (P < 0.01). On day 0, there were trends of differences (P = 0.0515) between patients with and without VOD in the levels of protein C. These results suggest P-III-P, t-PA and protein C are predictive markers for VOD after HSCT in adults. Moreover, the serum P-III-P level before start of conditioning might indicate patients at risk for developing VOD.

Is veno-occlusive disease a specific syndrome or the exacerbation of physiopathologic hemostatic changes in hematopoietic stem cell transplantation (HSCT)?

The objective of the present study was to analyze whether veno-occlusive disease (VOD) is based on specific findings or whether this syndrome is the exacerbation of changes in hemostatic parameters that develop following hematopoietic stem cell transplantation (HSCT). 40 patients undergoing HSCT were enrolled (6 allogeneic bone marrow transplantation and 34 peripheral stem cell rescue-2 allogeneic, 32 autologous). Measurements of hemostatic parameters (endothelial, hypercoagulability and fibrinolytic markers) were obtained prior to chemotherapy and weekly thereafter for 3 weeks. The incidence of VOD was 15%. HSCT showed a state of moderate hypercoagulability (increase of thrombin-antithrombin complex and fibrinogen, and decrease of Factor VII, Protein C, and antithrombin-III), probably as a consequence of marked endothelial damage (increase of von Willebrand Factor and tissue plasminogen activator). All these alterations create a potentially prothrombotic state, more pronounced in VOD. The decreasing incidence of VOD and the moderate disease in all patients suggest that increasing improvements in transplant strategies have reduced the risk and severity of a syndrome that at the beginning of the transplantation era was a leading cause of morbidity/mortality.

Prevention and treatment of hepatic venocclusive disease after high-dose cytoreductive therapy

Venocclusive disease of the liver (VOD) is one of the most common and serious complications following stem cell transplantation. High-dose chemotherapy or chemoradiotherapy injures the structures of Zone 3 of the liver acinus and produces the clinical syndrome of hepatomegaly or right upper quadrant pain, jaundice, and fluid retention. VOD occurs in up to 54% of stem cell transplant recipients and is fatal in 25-50% of them. While the clinical signs of VOD usually manifest during the first post-transplant week, late presentation can occur. The purpose of this review is to discuss the manifestations and pathophysiology of VOD and the options for prevention and treatment.